Turning gear for internal combustion engines



G. COSTELLI 3,293,924

TURNING GEAR FOR INTERNAL COMBUSTION ENGINES Dec. 27, 1966 2Sheets-Sheet 1 Filed March 18, 1965 Dec. 27, 1966 G. COSTELLI 3,293,924

TURNING GEAR FOR INTERNAL COMBUSTION ENGINES Filed March 18, 1965 2Sheets-Sheet 2 United States Patent 3,293,924 TURNING GEAR FOR INTERNALCOMBUSTION ENGINES Giuseppe Costelli, Turin, Italy, assignor t0 FiatSocieta per Azioni, Turin, Italy Filed Mar. 18, 1965, Ser. No. 440,840Claims priority, application Italy, Mar. 24, 1964, 6,885/ 64 Claims.(Cl. 746) This invention relates to a device for effecting axialshifting of the driving .pinion unit in an engine starter drive, of thetype comprising a fork acting on a shifting member mounted for rotationand axial displacement against the action of a spring on a helicallysplined sleeve which fits on a helically splined end of the shaft of theengine starter and is coupled through an overrunning clutch or a freewheel with the pinion arranged to engage the gear on the flywheel of theinternal combustion engine.

The object of this invention is to provide a shifting member for turninggears of the type referred to above, wherein said member is of simpleconstruction and comprises punch-ed components only, which do notrequire any further machining and can be easily assembled.

With the above and further objects in view, which will appear from theappended description this invention provides a turning gear foreffecting axial displacement of the driving pinion unit for enginestarter drives of the type referred to above, wherein the shiftingmember interposed between the actuating fork and sleeve slidably splinedto the end of the engine starter shaft, comprise two sheet metal discsslidably and rotatably mounted on the sleeve, said discs beinginterconnected by means of tabs and notches, so as to definetherebetween an annular groove in which a third disc is loosely mounted,the latter disc being acted upon by the limbs of the actuating fork, thefork cooperating with said third disc to keep it against rotation.

The invention shall be described in detail with reference to theaccompanying drawings showing embodiments thereof, and wherein:

FIGURE 1 is a side elevational view of a turning gear according to thisinvention,

FIGURE 2 is an axial view thereof,

FIGURE 3 is a part sectional view on line III-III of FIGURE 2,

FIGURE 4 is an exploded perspective view of the shifting member,

FIGURE 5 is an axial sectional view of another embodiment of theshifting member,

FIGURE 6 is an axial view of a further modification of FIGURE 2,

FIGURE 7 is a cross sectional view on line VII-VII of FIGURE 6, and

FIGURE 8 is a part sectional view on line VIII-VIII of FIGURE 6.

In the embodiment shown in FIGURES 1 to 4 a fork 7 fast with a controllever, is pivoted on a pivot 8 and operated in a known manner by anelectromagnet or a pull rod, not shown.

The fork 7 acts on a shifting member generally denoted by II, mountedfor rotation and axial displacement against the action of a spring 5 ona helically splined sleeve 6 mounted on an end of the shaft 12 providedwith corresponding splines 14 of the starting motor and coupled througha free wheel with a pinion 9 arranged to engage the gear on the flywheel(not shown) of the internal combustion engine.

The shifting member 11 is actuated by the fork 7, and comprises apunched sheet metal disc 2 rotatably mounted Patented Dec. 27, 1966 in acircular groove formed by two further punched sheet metal discs 1, 3coupled together.

The disc 2 is in the form of a circular ring provided with two radialfingers 2a protruding from the outer edge at diametrically oppositepositions, engaged in corresponding slots 7b formed in two limbs 7a ofthe actuating fork 7 so that the disc 2 cannot rotate during operationof the engine starter and disengage from the fork 7.

The member on which the disc 2 is mounted comprises a circular ring 1formed with four circumferential radial notches 1a, and a disc 3 formedwith a pressed boss so as to present two concentrical circular rings 3a,30 arranged on planes extending parallel with each other, spaced by acylindrical section 3d integral therewith. The disc 3 is provided withfour axial rectangular tabs 3b punched and bent from the inner edge ofthe smaller circular ring 30.

On assembly the disc 2 is fitted on the cylindrical section 3d of thedisc 3, whereupon the disc 1 is coupled with the disc 3 and secured tothe latter by inserting the tabs 3b into the notches 10 and bending themover. The two discs 1 and 3 are thereby spaced by the cylindricalsection 3d so that they leave an annular groove therebetween in whichthe disc 2 is rot-atably mounted.

The shifting member 11 is mounted on the sleeve 6 and the fingers 2a arefitted into the slots 7b of the fork 7.

The member 11 is prevented from slipping off the sleeve 6 by a stopmember 4 comprising a resilient retaining ring of circular orrectangular cross-section engaged by an annular groove in the sleeve.

FIGURE 5 shows a modification wherein both discs 1 and 3 are providedwith cylindrical bosses 1b, 3d, respectively, and radial coupling f-aces1c, 30, respectively. The discs are interconnected, similarly to thepreviously described construction, by means of tabs .and notchesprovided in the faces 10, 3c.

FIGURES 6, 7 and 8 show a further modification in which the disc 2 isdeprived of radial fingers indicated by 2a in FIGURE 4. The fork 7 isnow provided at the end of its limbs 7a with ears 7c bent to U-shape toengage from opposite sides the circumferential edge of the disc 2. Inorder to prevent the rotation of the disc 2 when the starter operatesand a consequent wear of cars 7c the disc 2 is formed with a axialprojection 13 on its circumference. l

The components of the shifting member 11 can be surface hardened inorder to reduce Wear from relative rotation.

In operation, the shifting member 11 is axially moved by the fork 7 andby compressing the spring 5 moves the pinion 9 into engagement with theteeth on the engine flywheel, not shown. Upon engagement the enginestarter is energized in a known manner, whereby the pinion 9, the freewheel 10, the sleeve 6, and the compression spring 5 rotate. Due to thespring reaction, the discs 3 and 1 of the member 11 also rotate, while,the disc 2 is held against rotation either by the fingers 2a engaged inthe slots 7b of the fork 7 (FIGS. 1 to 4) or by the projection 13abutting against one of the cars 70 (FIGS. 6 and 8).

What I claim is:

1. Turning gear for internal combustion engines for effecting axialdisplacement of the engine starter drive, of the type comprising a forkacting on a shifting member mounted for rotation and axial displacementagainst the action of a spring on a sleeve slidable by helical spliningon the end of the engine starter shaft and coupled through a free wheelwith the pinion engaging the engine gear on the flywheel of the internalcombustion engine, wherein the shifting member interposed between theactuating fork and the sleeve comprises two sheet metal discs freelymounted on the sleeve and interconnected by tabs and notches to definetherebetween an annular groove in which a third sheet metal disc isloosely mounted, and connecting means for connecting said third disc tothe actuating fork.

2. Turning gear as claimed in claim 1, wherein the two interconnecteddiscs mounted on the sleeve are spaced by a cylindrical boss fast withone of the discs and forming the bottom of the annular groove.

3. Turning gear as claimed in claim 1 wherein said third disc is in theform of a fiat circular ring and said connecting means comprises twodiametrically opposite radially extending fingers secured to thecircumference of said ring and a slot formed in the end of each limb ofsaid actuating fork into which said fingers project.

disc is in the form of a flat circular ring and said connect ing meanscomprises said actuating fork formed with U-shaped radially directedprojections on the limbs of the actuating fork adapted to embrace saidthird disc.

5. Turning gear as claimed in claim 4 wherein said third disc isprovided with an axially directed abutment on one face thereof adaptedto cooperate with said projections to limit relative rotation betweensaid third disc and said fork.

References Cited by the Examiner UNITED STATES PATENTS 3,182,515 5/1965Klein 74-7 4. Turning gear as claimed in claim 1 wherein the third 15MILTON KAUFMAN, Primary Examiner

1. TURNING GEAR FOR INTERNAL COMBUSTION ENGINES FOR EFFECTING AXIALDISPLACEMENT OF THE ENGINE STARTER DRIVE, OF THE TYPE COMPRISING A FORKACTING ON A SHIFTING MEMBER MOUNTED FOR ROTATION AND AXIAL DISPLACEMENTAGAINST THE ACTION OF A SPRING ON A SLEEVE SLIDABLE BY HELICAL SPLININGON THE END OF THE ENGINE STARTER SHAFT AND COUPLED THROUGH A FREE WHEELWITH THE PINION ENGAGING THE ENGINE GEAR ON THE FLYWHEEL OF THE INTERNALCOMBUSTION ENGINE, WHEREIN THE SHIFTING MEMBER INTERPOSED BETWEEN THEACTUATING FORK AND THE SLEEVE COMPRISES TWO SHEET METAL DISCS FREELYMOUNTED ON THE SLEEVE AND INTERCONNECTED BY TABS AND NOTCHES TO DEFINETHEREBETWEEN AN ANNULAR GROOVE IN WHICH A THIRD SHEET METAL DISC ISLOOSELY MOUNTED, AND CONNECTING MEANS FOR CONNECTING SAID THIRD DISC TOTHE ACTUATING FORK.